public void update(Input input) {
    if (firstIteration) {
      Entity.setGame(this);
      firstIteration = false;
    }

    level.update();
    overPlayer.update(input);
    underPlayer.update(input);
  }
 public void render(Graphics2D g2d, float interpolation) {
   level.render(g2d, interpolation);
   overPlayer.render(g2d, interpolation);
   underPlayer.render(g2d, interpolation);
 }